(a) Field
Exemplary embodiments of the invention relate to a method of manufacturing a liquid crystal display, and more particularly, to a method of manufacturing a liquid crystal display with improved a response speed of liquid crystal.
(b) Description of the Related Art
A liquid crystal display is one of the currently most widely used flat panel displays, and includes two display panels on which electric field generating electrodes, such as a pixel electrode and a common electrode, are provided, and a liquid crystal layer interposed between the two display panels. The liquid crystal display generates an electric field in a liquid crystal layer by applying a voltage to the electric field generating electrode, determines a direction of liquid crystal molecules of the liquid crystal layer through the generated electric field, and controls polarization of incident light to display an image.
Among the liquid crystal displays, a liquid crystal display in a vertically aligned mode, in which longitudinal axes of the liquid crystal molecules are arranged substantially perpendicular to upper and lower display panels when the electric field is not generated therein, has been in the limelight because of a high contrast ratio and easy implementation of a wide reference viewing angle.
In the liquid crystal display in the vertically aligned mode, a plurality of domains having different alignment directions of the liquid crystals may be provided in one pixel to implement a wide viewing angle.
The domains may be provided by a method of forming incised portions, such as slits, in the electric field generating electrodes. In the method, the liquid crystals are re-arranged by a fringe field formed between an edge of the incised portion and the electric field generating electrode facing the edge of the incised portion to provide the plurality of domains.
The domains of a liquid crystal display may be provided as a liquid crystal display in a vertical alignment (“VA”) mode, in which a domain forming unit is provided in both upper and lower substrates, or as a liquid crystal display in a patternless VA mode, in which a fine pattern is formed only on a lower substrate and a pattern is not formed on an upper substrate. A display area is divided into the domains by the domain forming unit, and the liquid crystals within the respective domains are tilted substantially in the same direction.
Recently, an initial alignment method, by which a liquid crystal has a pretilt angle when an electric field is not generated therein, has been suggested to increase a response speed of the liquid crystal while implementing a wide viewing angle. To provide the pretilt of the liquid crystal in multiple directions, the electric field is applied to the liquid crystal layer using an alignment layer having multiple alignment directions or adding an alignment supporting material to the liquid crystal to have a pretilt angle, and then the alignment supporting material is cured. The alignment supporting material cured by heat or light, such as ultraviolet ray, such that the liquid crystal may have the pretilt angle in a specific direction. When the electric field is generated in the liquid crystal layer to provide the pretilt angle, a voltage is applied to each of the electric field generating electrodes.
In a method of manufacturing the liquid crystal display, a plurality of cells is formed by providing multiple layered thin film patterns on a mother substrate through a deposition process and a photolithography process and cutting the mother substrate for each cell to manufacture the liquid crystal display. When a voltage is applied to the electric field generating electrodes in a process of aligning the liquid crystals, if the voltage is applied for each cut cell and ultraviolet ray is irradiated, a lot of time and equipment may be used, such that productivity is degraded.
Further, when the irradiated light does not sufficiently reach the liquid crystal layer when light, such as ultraviolet rays, is irradiated during the process of aligning the liquid crystals, the liquid crystals may not have a target pretilt angle, such that a response speed of the liquid crystal may be decreased and uniformity of an operation of the liquid crystal may be degraded when the manufactured liquid crystal display is driven.